RFR: JDK-8302801: Remove fdlibm C sources [v3]

Fri Mar 3 01:05:12 UTC 2023

On Fri, 3 Mar 2023 00:31:12 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Hotspot changes are okay but I'm a bit confused about what the hotspot code will now be used for?

`SharedRuntime::*` runtime math functions are used on platforms where there are no HW instructions or intrinsics (Zero VM). JIT compiled code may also call them in such case (or when intrinsics disabled with flag):
https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/library_call.cpp#L1815

Consider them as default intrinsics for all platforms (since they are written in C). They are faster than interpreting bytecode.

They are also needed for results consistency - the same code is used by Interpreter and JITed code.

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PR: https://git.openjdk.org/jdk/pull/12821